The present invention relates to a technical field of a seat-load measuring apparatus mounted under a seat rail for guiding a seat of a vehicle, such as a car, so as to measure the load imposed on the vehicle seat. More particularly, the present invention belongs to a technical field of a seat-load measuring apparatus having a connecting bracket that connects a base thereof to a seat rail.
Seat-load measuring apparatuses 104 have been proposed which are mounted under seat rails 103 for guiding a vehicle seat 102, on which a person 101 sits, in order to measure the load imposed on the vehicle seat 102, as shown in FIGS. 14(A) to 14(C). In each seat-load measuring apparatus 104, a lower surface of a base 105 that has an upward-pointing angular-U shape in cross section is fixed to a seat mounting section 107 of a vehicle body with seat brackets 106 at the front and rear ends therebetween, and the seat rail 103 and the base 105 are connected by a pin bracket (hereinafter also referred to as a rail bracket) 108 serving as a connecting bracket that has a downward-pointing angular-U shape in cross section. In this case, the seat rail 103 is firmly connected to the flat upper surface of the pin bracket 108, and a bracket pin (hereinafter also referred to as a stopper bolt) 109 is extended through pin holes 108a and 108b provided in the right and left side plates of the pin bracket 108 and pin holes 105a and 105b provided in the right and left side plates of the base 105, thereby connecting the seat rail 103 to the base 105 (for example, see Japanese Unexamined Patent Application Publication No. 2000-258234).
In a case in which a heavy load is imposed on the pin bracket 108 that connects the seat rail 103 and the base 105 of the seat-load measuring apparatus 104, for example, in a vehicle collision, the pin bracket 108 must have a sufficient strength to support the heavy load.
However, in the connecting structure for the seat rail 103 and the base 105 of the seat-load measuring apparatus 104 disclosed in the above Japanese patent publication only the bracket pin 109 extends through the pin holes 105a and 105b simply provided in the right and left side plates of the base 105 having an upwardly-pointing angular-U shape in cross section and the pin holes 108a and 108b simply provided in the right and left side plates of the pin bracket 108 having a downwardly-pointing angular-U shape in cross section. Therefore, the strength of the pin bracket 108 is insufficient. That is, the strength of the pin bracket 108 can be increased to some extent by increasing the dimensions of portions 108c and 108d of the pin bracket 108 having the pin holes 108a and 108b (for example, the thicknesses, and the distances from the pin holes 108a and 108b to the outer peripheral edge of the pin bracket 108). However, in such a case in which the dimensions of the portions of the pin bracket 108 having the pin holes 108a and 108b are simply increased, layout restrictions are increased, and the mounting flexibility is reduced.
Although a heavy load, for example, in a vehicle collision can be, of course, supported by the connecting structure using the pin bracket 108 disclosed in the above Japanese publication, it is preferable to more reliably support such a heavy load without increasing the layout restrictions.